I stayed at the Hilton Leningradskaya with my partner last month. There was a bit of mumbling at checkin, and they seemed pretty insistent on 'upgrading' us a room with 2 doubles (the same category as booked) when we booked a King, and my HH preferences are for one bed
On further enquiry it transpired that they had me down as HH Blue when I'm in fact Gold. Once that was sorted got upgraded to a Junior Suite, again with 2 doubles.
Apart from that everything was fine - so long as you don't make a show of things there'll be no trouble. I really enjoyed the Hilton, and it has a fantastic Exec lounge.
And yes, 30K for First on RFS is a steal! We did CE to Helsinki and onto Moscow via St Petersburg but the trip back in F was great